That spider bite looks like a brown recluse or hobo spider bite. Those spiders aren't that big, little more than a quarter for the big ones (leg span that is) I think. It's their venom, they usually bite humans if we lie down on one, or put our shoe on and they're inside. The bite can be painless and unnoticeable. After a while the venom starts to decay your tissue and shit. It's a necrotic type of venom. It's when you don't notice and leave it alone for a while that it can really do damage.

That one on the wall behind the clock is some large breed, I think from Australia. Pretty harmless if I remember correctly.

And that wierd one "camel spider"? What the fuck? Is that photoshopped?

EDIT: shit, the first spider bite I'm talking about. Rebgirls got some other brown recluse bites lol ... Spiders don't really scare me anymore, but I kill any spider that even looks remotely like a brown recluse, I fucking hate those things (and hobo spiders too).